Underwater kite device

ABSTRACT

A kite device to be towed in water which is adapted to carry various telemetering instruments for measuring schools of fish, depths of the sea and carrying out other functions, and which comprises a pair of frames disposed in the towing direction, a transverse main wing and tail surfaces extending between and connecting the pair of frames at the forward and aft parts thereof, respectively, a first deviation wing provided at a transversely outer position relative to one frame, and second deviation wing provided at a transversely outer position relative to the other frame, the hydrodynamic force created by the first deviation wing for moving the kite device in a transversely outward direction being greater than the force created by the second deviation wing for moving the kite device in the opposite transverse direction.

United States atent 1 Umazume 1 1 UNDERWATER KITE DEVICE [76] Inventor: Kousuke Umazume, 13-5, Z-chome,

Shimorenjaku, Mitaka-shi, Tokyo, Japan 1 [22] Filed: Nov. 30, 1972 [21] Appl. No.: 310,926

Primary Examiner-Milton Buchler Assistant ExaminerRandolph A. Reese Att0rneyEric H. Waters et a1.

[ 5 7 ABSTRACT A kite device to be towed in water which is adapted to carry various telemetering instruments for measuring schools of fish, depths of the sea and carrying out other functions, and which comprises a pair of frames disposed in the towing direction, a transverse main wing and tail surfaces extending between and connecting the pair of frames at the forward and aft parts thereof, respectively, a first deviation wing provided at a transversely outer position relative to one frame, and second deviation wing provided at a transversely outer position relative to the other frame, the hydrodynamic force created by the first deviation wing for moving the kite device in a transversely outward direction being greater than the force created by the second deviation wing for moving the kite device in the opposite transverse directron.

6 Claims, 6 Drawing Figures PM'ENTEU SEPZSIQH m1 er 2 FIG.2

FIG.5

UNDERWATER KITE DEVICE BACKGROUND OF THE INVENTION This invention relates to underwater drag devices resembling paravanes and kites which can be equipped therein with fish finders, sonar, acoustic fathometers and the like and towed by a ship by means of a rope. More particularly, the invention relates to a kite device which can be maintained below but near the surface of the sea with a part of the device maintained always above the sea surface.

Ordinarily, a fish finder or an acoustic fathometer is installed on board a ship to detect schools of fish or the depth of the sea at specfic areas. However, with these apparatus installed on board, the detection of fish or the depth of the sea in areas departing or offset from the course of the ship cannot be carried out. For this reason, a drag equipped with these apparatus is lowered into the sea, and towed with a rope in such a manner that the course of the drag departs from that of the ship to port or to starboard.

A conventional drag or kite comprises a frame body, a main wing, and a tail surface, so arranged that the kite is thereby caused to diveinto the sea when it is towed by a ship through a rope and to maintain a predetermined depth from the surface of the sea and a desired attitude independent of the cruising speed of the parent ship under the cooperative effect of the hydraulic resistance of the tow rope and the buoyant force (or diving force) created by the hydrodynamical effect on these wings.

The kite may also be provided with a vertical rudder and ailerons or the like movable surfaces or flaps. With the aid of these rudder and ailerons, the depressor can be moved in the sea along a three-dimensional course under the towing force of the tow rope, so that the de tection of fish, the depth of the sea, and other measurements can be accomplished from various positions offset from the course of the ship.

Because the kite is thus operated under water, the measurement data or measurands collected in the kite must be transmitted back to the parent ship through a supersonic system or a cable installed along or within the tow rope, or the data must be stored in a memory device provided in the kite to be read out later.

However, when the measurands are transmitted through a supersonic system, the distance between the ship and the kite becomes a problem. When the measurands are transmitted through the cable, the disadvantage of increased hydrodynamic resistance of the cable inevitably arises with resultant unsatisfactory diving performance of the kite. When the measurands are temporarily stored in the memory device, the read out time thereof may frequently be too late, rendering the information to be entirely useless.

Wireless transmission with one part of the kite being exposed to the air has also been attempted. In this case, however, the kite tends to lose its balance when the main wing is partly projected into the air under the action of turbulent waves, and it has been found difficult to tow the conventional kite slightly below the surface of the sea so that one part of the kite is always exposed to the air.

SUMMARY OF THE INVENTION tow rope, and wherein the three-dimentional position and attitude of the kite in the sea can be automatically controlled by self-contained component members.

Another object of the invention is to provide a kite which, in operation, is maintained partly above the sea level whereby the measurands collected in the kite can be transmitted through wireless communication to the parent ship.

The foregoing and other objects of the present invention can be achieved by a kite comprising a pair of frames extending in the towing direction in transversely spaced-apart relationship, a transversely extending main wing connecting the forward parts of the frames, a transversely extending tail surface connecting the aft parts of the frames, a second tail surface perpendicular to the transverse tail surface, a first deviation wing secured to one of said frames at transversely outer position relative to said one frame and shaped to move the kite hydrodynamieally in one transversely outward direction, and a second deviation wing secured to the other of said frames at a transversely outer position relative to said other frame and shaped to move the kite hydrodynamieally in the other transversely outward direction, the hydrodynamic moving force created by the first divation' wing being greater than that created by the second deviation wing. I

The nature, principle; and utility of the present invention will be more clearly understood from the following detailed description of the invention with respect to a preferred embodiment thereof when read in conjunction with the accompanying drawings, wherein like parts are designated by like reference numerals.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is an elevational view of a kite constituting a preferred embodiment of the invention, whichis shown as being towed in the sea in a substantially vertically erected state;

FIG. 2 is a front elevational view of the kite shown in FIG. 1; v

FIG. 3 is a plan view of the' kite observed from the line III-III in FIG. 1;

FIG. 4 is a bottom view of the kite observed from the line IV-IV in FIG. 1;

FIG. 5 is a perspective view of the kite shown in FIG. 1; and

FIG. 6 is a perspective view showing operating conditions of the kite shown in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. 1 through 5, the underwater kite shown therein and generally designated by reference numeral A, comprises a pair of upper and lower longitudinal frames 1 and 2 of substantially rectangular configuration, a main wing 3 connecting the front parts of the frames, a tail surface 4 connecting the rear parts of the frames which are thereby held in mutually parallel and spaced-apart relationship, and another tail surface 5 extending perpendicularly to the tail surface 4 at an intermediate position thereof. An upper pillar 7 and a lower pillar 9 are disposed on and extend upward and downward from the upper and lower surfaces of the frames 1 and 2, respectively, at positions alined with the main wing 3 disposed between these frames. A V- shaped first deviation wing 6 with a definite dihedral angle is secured to the upper end of the upper pillar 7,

and all of the above described components 1 through 7 and 9 are rigidly connected with each other thereby to form an integral body of the kite A.

A second horizontal deviation wing 8 is provided as a part of a streamlined'body also havng its own horizontal tail surface 12, and the body 10 is rockably connected to the lower end of the pillar 9 by means of a pivot pin 1 1.

When a rope R is attached to a point T on the main wing 3 and the kite A is operated in the sea in a vertically erected condition as shown in FIGS. 1 and 2, the first deviating wing 6 produces a buoyant or lift force while the second deviating wing 8 produces a negative lift or diving force exerted on the kite. The lift force is made greater than the diving force, and therefore the kite is lifted upward.

However, when the kite A is initially thrown into the sea, it assumes a horizontal attitude-as shown in the right-hand side of FIG. 6. As the kite A begins to be pulled or towed by a ship S through the rope R, the first deviating wing 6 which is now at the left-hand or port side of the kite creates a force tending to shift the kite leftward from the ships course and the second deviating wing 8 creates a force tending to shift the kite rightward or to starboard. Since the leftwardly moving force of the first deviating wing 6 is greater than the rightwardly moving force of the second deviating wing 8 as described above, the kite A is moved leftward as shown in the left-hand side of FIG. 6.

The kite A is thus moved along a three-dimensional path determined by the towing force of the rope R and various hydrodynamic forces caused by the main wing 3, tail surfaces 4 and 5, and the first and the second deviating wings 6 and 8, until the kite A is finally brought near the surface of the sea as shown in the lefthand side of FIG. 6.

When the kite A is brought near the surface of the sea, the main wing 3 and the tail surface 4 are disposed substantially vertically, and the kite is moved further upward until a part of the first deviating wing 6 projects above the surface of the sea into the air. The upward movement of the kite A stops when the lift force created by the first deviating wing 6 decreases as a result of the partial exposure thereof to the air, to a level equal to or balancing the diving force created by the second deviating wing 8 and force due to gravity. In this state, the kite is maintained at a level under the surface of the sea where the first deviating wing 6 is partly exposed to the air.

As described before, the second deviating wing 8 is formed integral with the body 10 having its own tail surface 12, and the body 10 and hence the tail surface 12 are freely rockable about the pivot pin 11. This freely swingable feature of the tail surface 12 is desirable to prevent the kite from undergoing excessive pitching motion due to forces of waves striking against the first deviating wing 6.

The upper and lower pillars 7 and 9 provide substantial transverse distances between the wings 3 and 6 and between the wings 3 and 8 and serve to prevent hydrodynamic interferences between the main wing 3 and the deviation wings 6 and 8.

Although the main wing 3 is shown to have a symmetrical cross-sectional configuration with respect to its longitudinal centerline, the main wing 3 may be so shaped that one side surface has a greater convexity than the other side surface, whereby the main wing is subjected to a hydrodynamic lateral force in the sea to be moved toward the side other than the side on which the rope is attached.

By such measures, the main wing of the kite can be more easily maintained in its vertical attitude, and the leftward departure of the kite from the ship s course is ensured. Furthermore, it will be apparent to those skilled in the art that the departure of the kite may be changed from the above described leftward movement to the rightward movement relative to the ships course when the position T at which the rope is attached is changed from one side of the main wing 3 to the opposite side.

When the first deviating wing 6 is partly exposed to the air, wireless transmission of measurands and the like can be established between the kite A and the parent ship S by utilizing an antenna (not shown) provided on the first deviating wing 6 above the sea level.

The kite according to the present invention thus permits continuous supply of information relating to schools of fish or depth of the sea in areas widely separated from the ships course. In addition, the kite may also be advantageously employed for measuring quantities in areas where hazardous flotsam and dangerous objects exist, to protect the ship from exposure to such hazards.

I claim:

1. A kite device adapted to be towed in water with a rope, comprising a pair of frames extending in the towing direction in parallelly spaced-apart relationship, a transversely extending main wing connecting the forward parts of the frames, a transversely extending tail surface connecting the aft parts of the frames, a second tail surface perpendicular to said transverse tail surface, a first deviation wing secured to one of said frames at a transversely outer position relative to said one frame and shaped to move the kite device hydrodynamically in one transversely outward direction, and a second deviation wing secured to the other of said frames at a transversely outer position relative to said other frame and shaped to move the kite device hydrodynamically in the other transversely outward direction, the hydrodynamic moving force created by the first deviation wing being greater than that created by the second deviation wing.

2. A kite device as set forth in claim I wherein said first deviation wing has a V-shaped configuration with a definite dihedral angle as seen substantially in the towing direction.

3. A kite device as set forth in claim 1 wherein said second deviation wing is rockable around a pin substantially perpendicular to the plane of said main wing.

4. A kite device as set forth in claim 1 wherein said second deviation wing is secured to a streamlined body pivotally mounted on said other frame, said body having a tail surface.

5. A kite device as set forth in claim 1 wherein said first and second deviation wings are secured to the respective frames through respective pillars providing substantial distances between the frames and the deviation wings.

6. A kite device as set forth in claim 1 wherein the tow rope is secured to one side of said main wing. 

1. A kite device adapted to be towed in water with a rope, comprising a pair of frames extending in the towing direction in parallelly spaced-apart relationship, a transversely extending main wing connecting the forward parts of the frames, a transversely extending tail surface connecting the aft parts of the frames, a second tail surface perpendicular to said transverse tail surface, a first deviation wing secured to one of said frames at a transversely outer position relative to said one frame and shaped to move the kite device hydrodynamically in one transversely outward direction, and a second deviation wing secured to the other of said frames at a transversely outer position relative to said other frame and shaped to move the kite device hydrodynamically in the other transversely outward direction, the hydrodynamic moving force created by the first deviation wing being greater than that created by the second deviation wing.
 2. A kite device as set forth in claim 1 wherein said first deviation wing has a V-shaped configuration with a definite dihedral angle as seen substantially in the towing direction.
 3. A kite device as set forth in claim 1 wherein said second deviation wing is rockable around a pin substantially perpendicular to the plane of said main wing.
 4. A kite device as set forth in claim 1 wherein said second deviation wing is secured to a streamlined body pivotally mounted on said other frame, said body having a tail surface.
 5. A kite device as set forth in claim 1 wherein said first and second deviation wings are secured to the respective frames through respective pillars providing substantial distances between the frames and the deviation wings.
 6. A kite device as set forth in claim 1 wherein the tow rope is secured to one side of said main wing. 